Allowing penetrating or blunt trauma patients to remain temporarily hypotensive in the field vs giving crystalloid volume resuscitation prior to definitive surgical repair improves mortality and seems to decrease blood loss and need for transfusion of blood products.
Why does this matter?
Prior studies suggested that normalizing blood pressure in patients with penetrating trauma before fixing the injuries worsened outcome. See this classic article and JF summary. This systematic review pooled both penetrating and blunt trauma patients.
Fix leaks. Then fill bucket.
This was a meta-analysis of 5 RCTs with 1158 patients - 2 with penetrating trauma only, 3 with both blunt and penetrating trauma. The studies generally excluded patients with traumatic brain injuries since we know hypotension is bad for these patients. Most of the individual studies were underpowered, small, and had issues with blinding. Despite that, when pooling the data, they found the odds of death dropped 30% in patients with permissive hypotension. The studies defined permissive hypotension as MAP goals > 50 mmHg and SBP goals > 70 mmHg. The more aggressive arms of the study gave IVF to maintain MAP > 65 mmHg and SBP > 100 mmHg. Permissive hypotension decreased blood loss and blood transfused in this group.
Permissive Hypotension vs. Conventional Resuscitation Strategies in Adult Trauma Patients with Hemorrhagic Shock: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Trauma Acute Care Surg. 2018 Jan 24. doi: 10.1097/TA.0000000000001816. [Epub ahead of print]
Peer reviewed by Thomas Davis, MD.